Welcome to opening Pandora's box, kid. There is loads out there, but mostly crap. A lot is ambiguous, so people tend to fill in their own interpretations. It's also a huuuuuge area to cover. I'll see if I can come up with some good sites or books, because it really is not a good thing to fuck around with. You get this wrong, you can get really messed up. Ask Runesinger, she knows all about it, too. Both of us know some of how to do things, neither one of us does it much. For a reason.

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I was born right the first time, no need to be born again.